Comparison of the Antibacterial Activity of the Seed Hull of Quercus Bantii on Some Gram Negative Entric Bacilli With Some in-Use Antibiotics

The rapid increase of antibiotic resistance especially among gram negative bacteria, has made the researchers to find an alternative substitutions for uneffective antibiotics and the candidate was herbal plants which their antimicrobial effects were understood traditionaly from the past. Since Oak seed hull (Quercus brantii) has been used in traditional medicine for treatment of diarrheal diseases, the role of methanol extract of the plant on few gram negative entric bacilli were evaluated and compared with some in-use antibiotics.

The methanol extract of the active constituents of the plant was concentrated with distillation apparatus in vaccume and was then diluted with methanol to yield different concentrations. The antimicrobial activity of the extract was then examined by standard MIC and disc diffusion method on E.Coli, Proteus, Shigella and Salmonella and compared with those of gentamicin, nalidixic acid and co-trimoxazole in the next step.

The results showed that the antibacterial effect of the methanol extract on proteus and E.coli wwas significant and directly related to its concentration but was not the same for shigella or salmonella. Some concentrations of the extract had a similar or better effect compared to nalidxic acid or co-trimoxazole. While the effect of 80% was not significant in general, except for salmonella that its effect was equivalent to 25mg co-trimoxazole.

The pverall results showed that although Oak seed hull has some antibacterial activity, but it seems that its anti-diarrheal effect id due to Tanins which cause water absorption and protein precipitation in the intestine as well.